The present invention relates to apparatus for supporting and/or holding parts which undergo expansion and contraction as a result of changes in temperature, pressure and/or other influences.
In many machines, aggregates, production lines and/or similar assemblies, numerous or certain parts (including, for example, boilers, heat exchangers, compressors, pumps, motors and/or others) undergo expansion or contraction under the action of changing temperatures and/or pressures. For example, the housing of a pump is likely to expand or contract in the axial direction as well as at right angles to such direction if the temperature and/or pressure of the fluid medium therein and/or therearound increases or decreases. In order to prevent excessive stressing of the material of expandible and contractible parts, they must be mounted in such a way that they can undergo repeated expansion and contraction without affecting their integrity, the integrity of their supports and/or the integrity of fasteners which secure the expandible and contractible parts to the supports. In other words, at least the majority of connections between an expandible and contractible part on the one hand and its support on the other hand must allow for a certain amount of play which is needed to prevent excessive stressing of such components. Furthermore, it is often necessary that the position of an expandible and contractible part with reference to another part of the same aggregate, assembly, machine or production line remain unchanged so as to ensure that such parts will be capable of continuous cooperation irrespective of changes in the dimensions of the expandible and contractible part. By way of example, the connection between the shaft of a centrifugal pump and the shaft of the motor which drives the pump shaft should remain unaffected by expansion and/or contraction of the pump housing.
Commonly owned German Pat. No. 1,027,515 discloses a system for mounting the housing of a pump, turbine or the like. The connection between the housing and its support (e.g., a base plate) is such that the housing can undergo axial expansion or contraction. To this end, the housing is provided with projections received in and movable lengthwise of suitable guides which extend in parallelism with the axis of the housing. The patented system is capable of preventing misorientation of the pump shaft because the housing is expandible and contractible in the longitudinal direction of the aforementioned guides which are parallel to the pump shaft. Furthermore, the legs of the housing are secured to the base plate by means of bolts which are designed in such a way that they allow for changes in the level of each leg as well as for movements of each leg in a plane which is parallel to the base plate. In other words, each of the legs is mounted with a certain amount of clearance so that it can move in several directions in response to expansion or contraction of its material and/or in response to expansion or contraction of the major part of the housing in the axial direction of the pump shaft. A drawback of the patented arrangement is that the expandible and contractible part is not guided and held with a requisite degree of accuracy and reproducibility, not only relative to the support but also relative to the component or components which cooperate therewith.